(a) The tax imposed by § 5502(a) of this title shall be collected by the distributor from the ultimate consumer as a separate item not included in the sales price or tariff charge. The amount of tax collectible from the ultimate consumer shall in each case be calculated on the basis of a uniform percentage of the sale price or tariff charge payable by the ultimate consumer for the commodity or service which is subject to tax under this section and shall in each case be computed to the nearest highest cent; provided, however, that such tax shall not apply to receipts derived through the use of automatic coin collecting machines or coin boxes. A distributor's gross receipts shall not be deemed to include any portion of the tax collected from its consumer.
(b) The tax imposed by § 5502(b) of this title shall be paid only once and shall be considered imposed upon, in the case of deliveries of gas or electricity described in § 5502(b)(3) of this title, the ultimate consumer or user for the use of such gas or electricity. In all other cases, the tax shall be imposed on the distributor and is not to be construed as a tax upon the consumer or user.